Congo red (CR) is an anionic azo dye widely used in many industries including pharmaceutical, textile, food and paint industries. The disposal of huge amount of CR into the various streams of water has posed a great threat to both human and aquatic life. Therefore, it has become an important aspect of industries to remove CR from different water sources. Molecular imprinting technology is a very slective method to remove various target pollutant from environment. In this study a precipitation polymerization was employed for the effective and selective removal of CR from contaminated aqueous media. A series of congo red molecularly imprinted polymers (CR-MIPs) of uniform size and shape was developed by changing the mole ratio of the components. The optimum ratio (0.1:4: 20, template, functional monomer and cross-linking monomer respectively) for CR1-MIP from synthesized polymers was able to rebind about 99.63% of CR at the optimum conditions of adsorption parameters (contact time 210 min, polymer dosage 0.5 g, concentration 20 ppm and pH 7). The synthesized polymers were characterized by various techniques such as Fourier Infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), and Brumauer-Emmett-Teller (BET). The polymer particles have successfully removed CR from different aqueous media with an efficiency of about ~ 90%.
The state of Johore suffered a massive flood disaster from 19th December 2006 to 1st January and from 12th January to 19th February 2007. The possible upsurge of dengue was of foremost concern and led to efforts in increasing control activities. Anyone with history of high fever with at least two symptoms of severe headache, pain behind the eyes, muscles and joint paint, rashes and petechiae were notified as dengue. Active and passive case finding was initiated at all 371 evacuation centres as well through health facilities and hospitals through an active surveillance system. Presumptive larval survey was also carried together with control activities by 46 health teams. Data were collected using the format ‘Aktiviti harian kawalan denggi di kawasan pos banjir- Lampiran E‘ and ‘Laporan aktiviti harian kawalan denggi di pusat pemindahan banjir – Lampiran D2’. Dengue serology and blood film for malaria was sent for as well as vector species identification. A total of 594 dengue cases were reported for the period of 19th December 2006 till 19th February 2007, which was an increase in comparison to the 5-year median but less than that reported in year 2006. However only 14 (2.3%) cases were from flood affected areas. During the flood phase, a total of 5,929 inspections were carried out at the evacuation centres with Aedes Index (AI) of 1.86%, while the post flood period showed a lower index. However Breteau Index (BI) and Container Index (CI) were higher. Preventive fogging were carried out at the evacuation centres using adulticides, thermal fogging was carried out at 21,959 premises (40.04% of inspected premises) and 350.6 L adulticides (malathion, fenitrothion and permethrin) were used. Dengue was expected to increase during flood as a result of increase Aedes potential breeding sites. However with intensive and integrated control activities, Johore was able to minimize the impact of flood for vector-borne diseases as seen from the low cases reported in flood related areas. A special guidelines for surveillance and control was developed during this flood as a reference for future occurrences.
The main objective of a root end filling material is to provide an apical seal that prevents the movement of bacteria and the diffusion of bacterial products from the root canal system into periapical tissues. The aim of this study was to compare the microleakage of three root end filling materials Mineral trioxide aggregate (MTA), Glass ionomer cement (GIC) and Silver GIC (Miracle Mix) using dye penetration technique under stereomicroscope. Forty-five extracted human maxillary central incisors were instrumented and obturated with gutta percha using lateral compaction technique. Following this, the teeth were stored in saline. After one week, teeth were apically resected at an angle of 90ï° to the long axis of the root and root end cavities were prepared. The teeth were divided into three groups of fifteen specimens each and were filled with Group I -MTA, Group II - GIC and Group III - Miracle Mix. The samples were coated with varnish and after drying, they were immersed in 1% methylene blue dye for 72 hours. The teeth were then rinsed, sectioned longitudinally and observed under stereomicroscope. The depth of dye penetration was measured in millimeters. Microleakage was found to be significantly less in MTA (0.83 mm) when compared to GIC (1.32 mm) (p < 0.001) and with Miracle Mix (1.39 mm) (p < 0.001) No significant difference was found when microleakage in Miracle Mix was compared to that of GIC (p = 0.752). Thus we concluded that MTA is a better material as root end filling material to prevent microleakage, in comparison to GIC and Miracle Mix.
Corrosion is a natural deterioration process that destructs metal surface. Metal of highly
protected by passivation layer such as Stainless Steel 316L also undergoes pitting corrosion
when continuously exposed to aggressive environment. To overcome this phenomenon, application
of epoxy based coating with addition of zinc oxide- poly (3,4-ethylenedioxythiophene)
doped with poly (styrene sulphonate) hybrid nanocomposite additive was introduced as
paint/metal surface coating. The compatibility between these two materials as additive
was studied by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD),
Field Emission Scanning Electron Microscopy/Energy-Dispersive X-ray spectroscopy (FESEM/EDX)
and Transmission Electron Microscopy (TEM) analysis. The effect of nanocomposite
wt.% in epoxy based coating with immersion duration in real environment on corrosion
protection performance was analyzed through potentiodynamic polarization analysis. The
main finding showed that addition of hybrid nanocomposite had increased corrosion protection
yet enhanced corrosion process when excess additives was loaded into epoxy coating.
Addition of 2 wt.% ZnO-PEDOT:PSS was found significantly provided optimum corrosion
protection to stainless steel 316L as the corrosion rate for 0 day, 15 days and 30 days of
immersion duration is 0.0022 mm/yr, 0.0004 mm/yr and 0.0015 mm/yr; respectively.
In recent years, there are growing trends in using palm oil as raw materials in radiation curable resins production. In this study, the acrylated palm oil resins i.e. the EPOLA (epoxidized palm oil acrylate) and the POBUA (palm oil based urethane acrylate) were synthesized using two different systems, i.e. the 25 liter pilot scale reactor synthesis system and the 2 liter (L) laboratory scale reactor synthesis system through chemical processes known as acrylation and isocyanation. In this
paper, the property of the acrylated resins which were produced by these two systems were evaluated and compared between each other. Their properties were characterized using the Fourier transform infrared (FTIR) spectrophotometer for functional group identification; the gel permeation chromatography (GPC) for molecular weight (Mw) determination, the Brookfield viscometer for viscosity measurements, the acid values (AV) and the oxirane oxygen contents (OOC) analysis. As a result, the production process for both the 2 L and 25 L reactor system were found to be time consuming and the main advantages for the 25 L reactor was its higher productivity as compared with the 2 L reactor system with the same synthesis process parameters i.e. the temperatures and the experimental methods. Besides that, the 25 L reactor synthesis
process was found to be safe, easy to control and served unpolluted process to the environments. The final products, the acrylated palm oil resins were formulated into ultraviolet (UV) curable compounds before subjecting them under UVirradiation. As a result, the UV-curable palm oil resins showed potential uses as pressure sensitive adhesives, printing inks including overprint varnishes (OPV) and coatings.
Diuron is an alternative biocide suggested to replace organotin in formulating antifouling paints to be applied on water-going vessels hull. However, it is potentially harmful to various non-targeted marine organisms due to its toxic properties. Present study aimed to isolate, screen and identify the potential of Diuron-degrading bacteria collected from the marine sediments of Port Klang, Malaysia. Preliminary screening was conducted by exposing isolated bacteria to 430ng/L (background level), followed by 600ng/L and 1000ng/L of Diuron concentrations. Nine bacteria colonies survived the exposure of the above concentrations. However, only two strains can tolerate to survive up to 1000μg/L, which were then characterised and identified using phenotypic tests and the standard 16S rRNA molecular identification. The strains were identified as Comamonas jiangduensis SZZ 10 and Bacillus aerius SZZ 19 (GenBank accession numbers: KU942479 and KU942480, respectively). Both strains have the potential of Diuron biodegradation for future use.